Graving dock and method of construction



Jan. 25, 1944. J. G. M KENZIE 2,340,005

GRAVING DOCK AND METHOD OF CONSTRUCTION Filed Oct. 51, 1940' 2 Sheets-Sheet 1 HTTOR/ EY- Jan. 25, 1944. 'J. G. MCKENZIE 2,340,005

GRAVING DOCK AND METHOD OF CONSTRUCTION F iled Oct. :51, 1940 2 Sheets-Shet 2 a. a. McKENZ/E INVENTOR.

Patented Jan. 25, 1944 CONSTRUCTION GRAVING DOCK AND Marnon or James G. McKenzie, Houston, Tex. Application October 31, 1940, Serial No. 363,651

1 Claim.

This invention relates to improvements in basin dry docks or graving docks and to the method of constructing such docks.

It is the primary object of the invention to provide a graving dock of novel construction, such dock being constructed by means of a novel method whereby there is a minimum of total cost and of delay in construction of the dock.

Another object class described in materials for the minimized.

a manner that operations and substructure for the dock are is to construct a dock of the Still another object is to construct a graving dock without the necessity of unwatering the site upon which such dock is to be constructed. Still another object is to construct a graving dock in a water covered area and in such manner that concrete is cast directly upon the surface of the excavated formation so that such concrete is accurately molded upon the foundation material.

A further object is to construct a graving dock by floating a combined reinforcing framework and form to a prepared, submerged site, lowering such framework into position upon the site and casting concrete in the framework and upon the foundation or bottom of the prepared site to form the reinforced dock.

A still further object is to provide a reinforcing framework including an enclosed structure forming inverted fluid tight chambers so that the entire framework may be floated into position over a prepared site and lowered upon the surface or foundation of such site. r The foregoing objects are primary objects and will, together with other objects be more fully apparent from the following description taken in connection with the accompanying drawings in which:

Fig. 1 is a transverse vertical section through a framework of reinforcing steel which is utilized in th practice of the invention.

Fig. 2 is a plan view of the framework shown in Fig. 1.

Fig. 3 is a side elevation of the framework shown in the preceding figures, such framework being shown in position preliminary to flotation to the pointof use.

Fig. 4 is a section or elevation through the completed graving clock.

The present invention is concerned in evading certain difiiculties and eliminating a material portion of expenses by minimizing both the material and labor necessary for the construcconcrete structure of the tion of graving docks. It has previously been proposed to construct graving docks by first unwatering the area upon which a dock is to be constructed. Thereafter suitable forms are constructed in such unwatered area by the use of supporting piling, concrete and reinforcing steel. The monolithic structure comprising the graving dock is fabricated within such area.

As indicated in the accompanying drawings, the present invention contemplates the initial construction of a framework I of structural steel which, as will more fully appear, subsequently comprises the reinforcing for the concrete of the finished structure. This framework i is of the general configuration of the finished docks and comprises side or wing wall portions 2 and 3 and a bottom portion 4.

As best shown in Fig. 3, this framework may be constructed upon ways 5 proximate the body of water 6 within which the graving dock is to be constructed. Alternately, of course, the framework may be constructed within a'shallow coffer dam proximate or remote from the body of water 6, the area upon which the framework is constructed being subsequently watered so that the framework may be floated therefrom to the final site of construction.

Referring more specifically to the construction of the framework l as shown in Figs. 1 and 2, it will be noted that such framework comprises a plurality of chord members it interconnected by suitable web members II which extend in such directions that the completed framework is capable of withstanding such stresses as will occur within the structure both during the period of construction and in the completed clock.

The side wings 2 and 3 are also provided with air tight sheathing l2 whereby suchwing portions are completely enclosed. The ends l3 of the side walls are also provided with air tight sheathing and it is to be understood that partitions M of such air tight sheathing will be provided in the side walls as desired. In order to provide satisfactory conditions whereby the completed structure may be floated to position, a. plurality of valves l5 are provided at the tops of the wing walls 2 and 3. v

When the framework I is prepared for floating into position for construction of the graving dock the valves l5 are closed so that the enclosed wing walls serve as pontoons or floats to support the entire frame structure. If increased buoyancy is desired the valves l5 may be opened and any gaseous fluid, such as air, may be forced into the wing walls to increase the buoyant effect thereof. Normal buoyancy or this increased buoyancy may be supplemented by the provision of additional air tight sheathing l2 to form any desired number of cells IS in the base or bottom portion 4. These cells are provided with valves l5 to be operated in conjunction with valves |5 to admit or withdraw air therefrom.

As best seen in Fig. 4, the site for the dock is prepared by providing an excavation having a lower surface 2| upon which the completed dock is to rest. Spaced rows of upwardly extending piling 22 cooperating in groups with inclined piling 23 are provided in the surface 2| and in such spaced relation that the framework I may be positioned and supported therebetween. The number of piles per group and the longitudinal spacing of the pile groups are adequate in bearing capacity merged framework.

Supporting brackets 25 are attached at in tervals to the framework in the wing walls 2 and 3 and extend outwardly therefrom. The pairs of piling 22 and 23 are provided in such spaced intervals that a jack 26 may be interposed between the upper end of the piling of each group and a supporting bracket 25.

If the earth formation 2| forms a solid foundation no further preparation is necessary for the construction of the dock in accordance with the present invention. It is intended that the concrete of the dock shall be cast directly upon this foundation surface 2| and will therefore follow intimately the contour of the foundation to distribute the loadover such surface and to equalize stresses throughout the structure. If, however, the dock is to be constructed on an area incapable of supporting the load then a foundation of piling in the surface 2| will be provided. It maybe noted that by virtue of the manner of constructing the dock, however, it is possible to use a relatively limited number of piling for this purpose because of the intimate relation between the dock structure and the prepared supporting surface or foundation. This feature is a factor in the reduction of cost in both material and labor. Furthermore, it is to be noted that by virtue of the method of construction it is unnecessary that the upper ends of the piling used under such circumstances be leveled off for desirable use of such piling within the structure.

By way of summary, it may be stated that in the construction of a graying dock in accordance with the invention it is contemplated that the framework I will be fabricated in a dry area and will subsequently be floated in the body of water 6. The framework will then be transported by flotation to a point over the excavation 23 whereupon air entrapped within the wing walls 2 and 3 will be controllably exhausted therefrom by operation of the valves l5. In this manner the framework will be controllably lowered until it engages. the jacks 2.6 whereupon the final step of leveling will be controlled by these jacks.

When the framework i is in place upon the surface 2| the concrete is poured under water about the portion 4 and within the wing Walls 2 to support the suband 3. It is obvious that, valves l5 and I5, having been opened during the watering operation just described, concrete may be introduced to the wings 2 and 3 and to the cells l6 through these open valves or, if desired, through suitable openings in the sheathing l2 and I2. It is desirable that the chord and web members l0 and H in the bottom portion 4 be completely covered by concrete. and preferably that there be a minimum coverage of four inches of concrete over such members. Completion of the filling of the wing walls 2 and 3 completes the construction of the dock whereupon the piling 22 and 23 may or may notbe removed from the dock site as desired.

Numerous advantages of my invention will be apparent to those skilled in the art. It may be pointed out in addition to the advantages already enumerated that the entire structural steel framework is relatively light, is strong about any axis and is readily maneuverable to bring into final position for the pouring of concrete about the chord and web members and the bottom 4 of the wing walls 2' and 3'.

The sheathing |2 on the wing walls, having served its purpose during the period of construction of the dock, remains in place and assists in protecting the structural frame work encased within the concrete of the monolithic structure resulting in the invention.

Attention is also again directed to the factor of saving in materials in that the amount of piling necessary for completion of the structure is minimized particularly due to the fact of the intimate bond between the surface 2| and the lower face of the completed structure. By virtue of this feature a portion, and in some instances all, of the superimposed load may be supported by the foundation subsoil in contact with the bottom of the unitary completed structure.

The foregoing description refers to specific structural features and technique in my method of constructing graving docks. It is to be understood, however, that the invention is not confined to such specific features of the disclosure, but

' broadly comprehends the provision of a graving dock of novel construction and by means of a technique whereby the cost of such construction is minimized and the time required for construction is materially decreased.

What is claimed is The method of constructing a graying dock which has an open steel frame work for the bottom and airtight orbuoyant wing wall enclosures which comprises the steps of excavating in water an area approximating the area to be occupied by the dock, floating the frame work to the site by the buoyant support of the wing walls, said enclosures being utilized as the fioating support, watering the enclosures by releasing air from the wing walls to admit water approximately at the bottom thereof, and lowering the frame work upon the base of the excavation, and depositing concrete within and through said frame work and wing walls and directly upon the surface within the area to form the bottom foundation having maximum contact with the supporting area and side. walls of the dock.

JAMES G. MCKENZIE. 

